140

36

84+56 = 140

12x3 = 36

k hộ mình nha

84 + 56

= 140

12 x 3

= 36

chúc pạn học giỏi

a, Ta có: 24 =  2 3 . 3 ; 10 = 2.5

=> ƯCLN(24;10) = 2

BCNN(24;10) =  2 3 . 3 .5 = 120

b, Ta có: 150 =  2 . 3 . 5 2 ; 84 =  2 2 . 3 . 7

=> ƯCLN(150;84) = 2.3 = 6

BCNN(150;84) =  2 2 . 3 . 5 2 . 7

c, Ta có: 140 =  2 2 . 5 . 7 ; 210 = 2.3.5.7; 56 =  2 3 . 7

=> ƯCLN(140;210;56) = 2.7 = 14

BCNN(140;210;56) =  2 3 . 3 . 5 . 7 = 840

d, Ta có: 105 = 3.5.7; 84 =  2 2 . 3 . 7 ; 30 = 2.3.5

=> ƯCLN(105;84;30) = 3

BCNN(105;84;30) =  2 2 . 3 . 5 . 7 = 420

[(4.x-72):2-84].28=65

[(4.x-72):2-84]=2

[(4x-72):2=86

(4.x-72)=172

4x=344

x=86

[ ( 4 . x - 72 ) : 2 - 84 ] . 28 = 56

[ ( 4 . x - 72 ) : 2 - 84 ] = 2

( 4 . x - 72 ) : 2 - 84 = 2

( 4 . x - 72 ) : 2 = 86

4 . x - 72 = 172

4 . x = 244

      x = 61

[ ( 4 . x - 72 ) : 2 - 84 ] . 28 = 56

[ ( 4 . x - 72 ) : 2 - 84 ] = 2

( 4 . x - 72 ) : 2 - 84 = 2

( 4 . x - 72 ) : 2 = 86

4 . x - 72 = 172

4 . x = 244

      x = 244 : 4

       x = 61

5^56=25^28

3^84=27^28

=>5^56<3^84

\(\dfrac{120}{150}+\dfrac{15}{27}=\dfrac{4}{5}+\dfrac{5}{9}=\dfrac{36}{45}+\dfrac{25}{45}=\dfrac{61}{45}\)

b

\(\dfrac{42}{49}+\dfrac{56}{84}=\dfrac{6}{7}+\dfrac{14}{21}=\dfrac{18}{21}+\dfrac{14}{21}=\dfrac{32}{21}\)

150/120 + 15/27
= 5/3 + 5/9
= 20/9

42/49 + 56/84
= 6/7 + 2/3
= 32/21

\(\dfrac{150}{120}+\dfrac{15}{27}=\)

 \(\dfrac{4}{5}+\dfrac{5}{9}=\dfrac{36}{45}+\dfrac{25}{45}=\dfrac{61}{45}\)

b.\(\dfrac{42}{49}+\dfrac{56}{84}\)

= \(\dfrac{18}{21}+\dfrac{14}{21}\)

= \(\dfrac{32}{21}\)

c, 36/84 nhe

Trả lời :

Đáp án : c, 36/84 .

CHÚC BẠN HỌC TỐT!

ý c bạn nhé

a,4

b,47

c,28

k nha

9-5=4

2+45=47

84-56=28

Tíck cho mình nha Mo Ni Ka ma Kết

hải bn đều đúng vậy thì kết bn với m , m k cho